English

Long baseline neutrino experiments, mass hierarchy and delta(CP)

High Energy Physics - Phenomenology 2013-02-05 v1 High Energy Physics - Experiment

Abstract

We investigate the possibilities offered by the long baseline experiments T2K, Noν\nua, LBNE and LAGUNA for the evaluation of the neutrino mass hierarchy and CP violating phase δCP\delta_{CP}. We consider a neutrino and antineutrino energy in the interval [0.5,12] GeV. It is found that the clearest possible distinction between the two hierarchy signatures is provided by LAGUNA for an (anti)neutrino energy E(νˉ)ν0.5E_{(\bar\nu)\nu}\simeq 0.5 GeV in the (νˉμνˉμ)νμνμ(\bar\nu_{\mu} \rightarrow \bar\nu_{\mu}) \nu_{\mu}\rightarrow \nu_{\mu} disappearance channel. For LBNE at Eνˉ1E_{\bar\nu}\simeq 1 GeV the νˉμνˉμ\bar\nu_{\mu}\rightarrow \bar\nu_{\mu} channel may also provide a distinction, although not so clear, and for Noν\nua this may be even less clear. These results are essentially the same for the θ23\theta_{23} first and second octant solutions. As for δCP\delta_{CP} determination, LAGUNA also offers the best chances at Eνˉ0.5E_{\bar\nu}\simeq 0.5 GeV in the νˉμνˉe\bar\nu_{\mu}\rightarrow \bar\nu_{e} channel with θ23\theta_{23} in either octant. Regarding nonstandard interactions, the best possibility for their investigation resides in Noν\nua whose source-far detector distance can become a magic baseline if the hierarchy is normal for channels νμνμ\nu_{\mu}\rightarrow \nu_{\mu}, νˉμνˉe\bar\nu_{\mu}\rightarrow \bar\nu_{e}, νˉμνˉμ\bar\nu_{\mu}\rightarrow \bar\nu_{\mu} with energy (8.9-9.1) GeV, (11.6-12) GeV, (8.8-12) GeV. If the hierarchy is inverse, magic baselines for Noν\nua occur for νμνe\nu_{\mu}\rightarrow \nu_{e}, νμνμ\nu_{\mu}\rightarrow \nu_{\mu}, and νˉμνˉμ\bar\nu_{\mu}\rightarrow \bar\nu_{\mu} with energy (11.8-12) GeV, (8.9-12.3) GeV, (8.8-8.9) GeV. For LAGUNA a magic baseline appears for the νˉμνˉμ\bar\nu_{\mu}\rightarrow \bar\nu_{\mu} channel only at (4.7-5.0) GeV in inverse hierarchy. We have also investigated a possible complementarity between T2K and Noν\nua.

Keywords

Cite

@article{arxiv.1302.0779,
  title  = {Long baseline neutrino experiments, mass hierarchy and delta(CP)},
  author = {C. R. Das and Joao Pulido},
  journal= {arXiv preprint arXiv:1302.0779},
  year   = {2013}
}

Comments

26 pages, 10 figures